Membrane separation has been widely recognized as an energy-efficient technology with a rapidly growing market. However, such growth raises concerns about sustainability due to current fabrication methods that employ toxic solvents and non-degradable petroleum-based polymers. The focus of tackling these challenges has been on the active layer of membranes via renewable materials, while the equally important membrane supports are yet to turn green. Herein we report the fabrication of sustainable, biodegradable, non-woven composite membrane supports made from three renewable materials: bamboo fiber, poly(lactic acid) (PLA) and dimethyl carbonate. The bio-based membrane supports exhibited a porous structure (porosity of 0.719 ± 0.132) with tensile strength (32.7-73.3 MPa) comparable to conventional materials, such as polypropylene. The microstructure and porosity of the supports were revealed by laser scanning confocal microscopy. The increase in bamboo content resulted in increased mechanical stability, decreased swelling and enhanced permeance, up to 1068±32 L m-2 h-1 bar-1 in water. The long-term chemical stability of membrane supports was verified in 19 of the 25 organic solvents screened. In particular, they were found to be stable in some conventional and emerging green polar aprotic solvents including Cyrene, 2-methyltetrahydrofuran, γ-valerolactone and propylene carbonate. Stable cross-flow filtration performance over 2 weeks was successfully demonstrated. The results demonstrated that the bamboo/PLA membrane supports could provide a sustainable alternative for conventional membrane backing materials by eliminating the need for petroleum-based non-degradable polymers and toxic solvents.

The main objective of this study is to explore the potential of using totally green composites made from renewable resources in packaging applications as compared to conventional thermoplastics. In this work, we undertook a comparative study of the functional properties related to the packaging applications of bamboo fabric–Polypropylene (PP) and bamboo fabric–Poly(lactic acid) (PLA) composites. Results indicate that Charpy impact strength was increased from 37.5 to 126 J/m for bamboo fabric–PLA composites and 204 to 278 J/m for bamboo fabric–PP composites compared to the pure polymers. Drop weight impact tests were also performed and the same trend was observed. Results of thermogravimetric analysis, differential scanning calorimetry, and heat deflection temperature analysis have shown that the addition of bamboo fabric improved the thermal resistance of these composites. Results indicate that bamboo fabric is a potential reinforcement for PLA composites, but possible packaging applications should avoid high humidity environment. POLYM. COMPOS., 35:1888–1899, 2014. © 2014 Society of Plastics Engineers

The objective of this study is to investigate the performance of bamboo fabric–poly(lactic acid) composites manufactured by compression moulding. The effects of compression moulding parameters on the mechanical properties of the bamboo fabric–poly(lactic acid) composite sheets were evaluated. Optimum compression moulding parameters to achieve the “best” mechanical properties of the composites was determined using the Taguchi method of experimental design. A rheology test was also conducted to measure the viscosity of the poly(lactic acid) at different temperatures. The processing parameters were found to affect the consolidation and quality of the composites. It appeared that the impact strength of the bamboo fabric–poly(lactic acid) composites in warp direction was enhanced by 240% in comparison to pure poly(lactic acid), whereas the improvements of tensile and flexural properties were lower than expected. When compared with theoretical predictions, the measured values of warp and weft tensile modulus show good agreement than those predicted by rules of mixture. On the other hand, the experimental values of tensile strength were lower than theoretical values due to poor fibre matrix adhesion.

Polylactic acid (PLA) was reinforced with either bamboo or jute fabric to produce 30 wt% composites. However, hydrophobic PLA and hydrophilic natural fiber are incompatible. Hence, maleic anhydride grafted PLA (PLA-g-MA) used as compatibilizer. In this study, effect of grafting reactants content, maleic anhydride (MA) and dicumyl peroxide (DCP) on MA grafting degree of PLA-g-MA were optimized using Taguchi experimental design. Synthesized PLA-g-MA exhibiting highest MA grafting degree used as compatibilizer at 3 wt%, 5 wt%, and 10 wt% for 30 wt% composites. These compatibilized 30 wt% composites were investigated for their water absorption, thermal stability, thermal, mechanical, and dynamic mechanical properties. PLA-g-MA addition at 3 wt% onto 30 wt% bamboo/PLA or at 5 wt% onto 30 wt% jute/PLA enhanced their interfacial adhesion, increasing their T g , T m , X c , tensile, flexural, impact and storage modulus but reduced their water absorption, T cc and damping factor. Further PLA-g-MA addition above 3 wt% onto 30 wt% bamboo/PLA or above 5 wt% onto 30 wt% jute/PLA adversely affected their water absorption, thermal, mechanical and dynamic mechanical properties. This was attributed to excess uncoupled PLA-g-MA acting as plasticizer. Adverse effects also observed for their thermal stability when PLA-g-MA was added onto 30 wt% bamboo/ PLA or 30 wt% jute/PLA. This was attributed to higher grafting reactant content, MA and less thermally stable PLA-g-MA.

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